When you book a full-truckload shipment, the carrier will transport only your freight. Whether you fill the whole truck with your goods or not does not matter. You do not have to share the truck with other companies and the carrier transports your freight directly from location A to location B. Whether you need a FTL shipment depends on the weight of your cargo as well as the space it occupies. FTL transports are useful if your freight completely fills a truck, if it is time-critical, if you prefer, that the truck only transports your cargo and/or if it the weight is that high that an FTL transport would be more cost-effective.